OK, I’m fairly new to brewing, but I’m pretty sure the laws of physics still apply. Last brew day while chilling the wort, I used a floating thermometer to let me know when it was time to transfer and pitch. It read about 80F and I was about to start siphoning when I checked it with one of those little instant read thermometers from NB, which read 130F. OK, maybe the first one was floating too close to the wort chiller. But moving things around and trying different angles still produced a 40ish degree difference. later I stuck both in the snow, and after 10 minutes there was a 10 degree difference.
So, Is it possible for a standard thermometer to be off, or does the digital need to be calibrated, and if so, how